How Long Does Nifedipine Stay In System Post Withdrawal?

I was given calcium channel blocker..Nifedipine to improve my blood circulation.I have type2diabetes and microcircuIation problem in my toes leading to blue toe syndrome.I donot have hypertension.After taking Nifedipine for six days I started having headache and drowsiness.My doctor asked me stop taking it.It has been a week since I stopped but the side effect continues.My research says sometimes it takes up to 12days to get it out of the. system.Worried.please advise.